Over the weekend, I broke down all of the details and differences between the new unlimited data plans being offered by the four major United States carriers. Of course, as I and many others were quick to point out, these plans aren’t technically unlimited as once you hit a certain amount of data, you may be throttled.

The trend of carriers ending contract pricing continues today. According to an internal leaked document obtained by Android Central, Sprint smartphone subsidy options are now limited to customers who wish to add a line to an existing account or upgrade their existing phone. This move follows AT&T’s announcement that it will stop offering two-year contracts this week, as well as Verizon, who simplified its offerings last August.

T-Mobile is bringing back one of its most popular promotions by — once again — offering four 10GB data lines for $120 total. The offer is available for a limited time from today, and is ideal for data-hungry families needing multiple lines. With no overages, you know exactly what your bill’s going to be every month too.

If you don’t need four lines, you can get two 10GB lines at $50 each:

With #10Gigs4All, two people can get up to 10 GB of 4G LTE each – no sharing required – for just $100 a month. Then, each additional line is just $20 more per person – also with 10 GB of T-Mobile’s blazing-fast 4G LTE. Now, with this promotion, that 4th line is free, bringing the total cost to just $120 per month for a family of four.

As with every Simple Choice plan, customers signing up get access to a host of awesome offers including rollover data for up to 12 months, Wi-Fi calling, unlimited music streaming and unlimited in-flight texting with GoGo. Customers also get unlimited calls to and from Mexico and Canada, as well as the ability to use 4G LTE data from their plan allowances in those countries, unlimited data and texts in 140 countries abroad and unlimited international texts from the US. Compared to the other three carrier options, it looks a fantastic deal:

This news comes just weeks after the carrier announced some killer iPhone deals, where customers were offered the new iPhones for $5 per month if they trade in their old ones.

Sprint today announced a new $22/month upgrade option for iPhone users allowing them to pick up a new iPhone at anytime through a plan dubbed “iPhone Forever”.

iPhone users can now opt to pay an extra $22/month on top of any individual unlimited plan or family share pack plan and when a new iPhone is eventually released, they simply bring in their old device to upgrade to the latest entry-level iPhone model. Here’s how it compares to options from the other carriers…expand full story

Verizon will launch brand new, simpler data plans and kill subsidies as expected from August 13. Today, the company introduced a set of plans which will require customers to pay for their smartphones in monthly installments, or buy them outright, instead of having the cost subsidized.